code: def test_tanh(backend_default):
      inputs = np.array([0, 1, -2]).reshape((3, 1))
      outputs = np.array(
          [true_tanh(0), true_tanh(1), true_tanh(-2)]
      ).reshape((3, 1))
      compare_tensors(Tanh(), inputs, outputs, tol=1e-7)
  
imports: from math import tanh
  import numpy
  from neon import NervanaObject
  from neon.transforms import Identity, Rectlin, Softmax, Tanh, Logistic, Sign, PixelwiseSoftmax
  from utils import allclose_with_out
label_desc: Use image node_id 21 for calling a global function with example usage: test_tanh(backend_default) without return types